April 15, 2009

Why Maybe I Shouldn't Teach Math

My eldest son is in Algebra I.

I see this often.

Kids 'get' when they are adding fractions that they have to have a common denominator. Get into Algebra and suddenly the denominators are different with variables, and they get all whack.

They don't understand and don't know what to do... or why they're doing it.

And so tonight I sat down to work with my son, to teach him how to add rational expressions, the following conversation ensued to the best of my recollection:

(Sidenote, we were adding 1/(1+x) + 1/(1-x) )

Me: You can't add them together. I know you think you can, but they aren't the same on the bottom.

Ringo: But I don't get it...

Me: It's like fractions. They have to look EXACTLY the same. The equation has to be completely EQUAL on both bottoms to add or subtract them.


Me: You don't see it.

Ringo: NO.

Me: Look. Cats and dogs can't mate and have babies. Giraffes and elephants can't mate and have babies. People and animals can't mate and have babies. Everyone can only mate with their like kind... cats and cats, dogs and dogs, people and people. Same same.


Me: Its the same in math. You can't mate equations unless the bottoms look exactly the same. They both have to be cats or humans. You can't mix animal types.

Ringo: OH! I get it!


Go figure. But, hey, he got it.

I felt like a sequal to Ghostbusters...

Posted by Boudicca at April 15, 2009 09:13 PM

So much more inventive than me... I would've said let's just stick a random number in X... what if X = 2

then 1+X is 3 and 1-X is -1

Can you add 1/3 and 1/-1???


See this is why I'm not a teacher - he'd look at me like I was nuts or something and say "well I still don't get it"

Then I'd have to scream and go running from the house.

Posted by: Teresa at April 17, 2009 05:10 PM

That's EXACTLY how to teach. You have to try to find a meaningful way for them to make a connection. Education is all about making links to previous knowledge. And being 'silly' with it takes the edge off of the stress of trying to understand something new.

You go, girl!

Posted by: Mrs. Who at April 18, 2009 01:03 PM

Beats my cheesey explanation of logs.

Posted by: PeggyU at April 18, 2009 09:19 PM